Children's heart surgery at Leeds General Infirmary will restart on Wednesday, NHS England has said.

Operations were halted at the unit last month after concerns were raised over death rate data and other issues - a decision that provoked anger, surprise and dismay from campaigners who had been fighting to keep open the threatened centre.

Last week, after a series of high-levels meetings, the hospital announced it would be allowed to restart surgery if a team of experts gave the necessary endorsements.

In a statement, NHS England said: "Children's heart surgery at Leeds General Infirmary can begin a phased restart on Wednesday."

NHS England said it originally raised concerns about services at the LGI because of preliminary data suggesting high mortality, concerns about staffing levels, whistleblowing information from clinicians, and complaints from patients.

Its statement said the decision to start a phased resumption "follows completion of the first-stage of a review by a multi-disciplinary independent clinical team, which has been working to establish the immediate safety of the unit: "NHS England has accepted the trust's recommendation, supported by independent experts, that surgery should resume gradually over the next month, starting with lower-risk cases. The second stage of the review will now begin looking at other areas where improvement may be necessary."

It said this second stage will involve a review of the way complaints from patients are handled and completion of a review of patients' case notes over the last three years.

The Leeds centre has been earmarked for permanent closure following a nationwide review of children's cardiac services in England. But the campaign group organised to fight that decision won a major victory in the High Court just a day before NHS England arrived in the city with concerns about the unit which forced the suspension of surgery.

Maggie Boyle, chief executive of the trust, said: "We stated on Friday that we wished to restart surgery once our partners were as confident in our staff and services as we are. I am delighted to say we are now reopening the unit having had the quality of our service independently verified by the Care Quality Commission, NHS England and the NHS Trust Development Authority following a rapid review process which took place over the weekend."

The Save our Surgery (SoS) campaign group said it was relieved the unit was to reopen but had numerous concerns about the decision to close the unit after the High Court judgment. An SoS spokeswoman said: "Save our Surgery is relieved that the children's heart unit is to reopen, ending a very difficult period for all connected to the children's heart surgery service at Leeds General Infirmary. Our main focus since the suspension of the service has been on ensuring surgery resumes as quickly as possible, however we do have numerous concerns about the chain of events that led to this decision."